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Marketable Securities (Details 2) - USD ($) $ in Thousands	Jan. 31, 2017	Jul. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses	$ 125	$ 181
Fair Value	29,197	10,716
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses	1
Fair Value	3,164
Federal Government Sponsored Enterprise notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses	23
Fair Value	6,265
International agency notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses	10
Fair Value	643
Mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses	1	39
Fair Value	2,600	5,082
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses	13
Fair Value	2,239
U.S. Treasury notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses	68	1
Fair Value	4,408	199
Municipal bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses	9	1
Fair Value	$ 9,878	3,112
Equity [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses		140
Fair Value		$ 2,323

X

- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

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X

- Definition

This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
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